Centrifugal projecting machine

ABSTRACT

A centrifugally projecting apparatus is provided to allow a liner to be easily exchanged, to prevent projecting members from projecting through the connected parts of the liner components, and to prevent an impeller cover from being abraded. The apparatus comprises bolts  36, 36   a  and a fixing member (hook members  24, 24 ) to press first and second-side liner components  31, 31 A, front and rear-side liner components  34, 34 A, and a frame-liner component  37  against a ceiling-side liner component  39  so that they are fixed to each other.

FIELD OF INVENTION

The present invention relates to a centrifugal apparatus for projectingshots for a shot blast machine. Particularly, it relates to a mechanismto prevent a cover for an impeller from being abraded.

BACKGROUND OF THE INVENTION

Conventionally, liners are put on the inner side of a cover for animpellers so that they surround the impeller of a centrifugal apparatusfor projecting shots for a shot blast machine to prevent the cover frombeing abraded. Also, the liners are divided into pieces and used forfront and rear sides, right and left sides, and an upper side. Thesesides are named based on the direction that the impeller rotates. Thepieces are also divided into small pieces. Thus there is a problem inthat there are too many pieces. Japanese Utility Model No. 2506549discloses an improvement of the liners that are located at the front andrear sides. The liners are formed as U-shaped rain gutters as viewedfrom their cross-sections, so that the number of pieces may bedecreased.

When any piece of the liners is abraded, a new one replaces it. Thepieces of liners are engaged by screws to the cover for an impeller.When they are replaced, those screws must be unscrewed to remove thepieces from the cover. Then, new ones replace those pieces. Thesereplacements are troublesome.

Because the pieces of the liners are screwed to the cover, the piecestend not to closely contact the cover. Thus, those connections areeasily abraded by shots. Thus, projecting members (shots) are projectedout of the connections. Thus, the cover is also abraded.

This invention has been conceived to overcome the problems referred toabove. The object of this invention is to provide a centrifugalapparatus for projecting shots wherein liners that have been abraded canbe easily replaced by new ones, and wherein shots are prevented frombeing projected through the connection between the pieces and the cover,so that the cover can be definitely prevented from being abraded.

SUMMARY OF THE INVENTION

Thus, the object is achieved by the centrifugal apparatus for projectingshots of this invention. The apparatus comprises an impeller, a coverfor the impeller surrounding it, and a liner that is located within thecover. The cover is comprised of first and second-side cover componentslocated at right and left sides, front and rear cover components, and aceiling cover component that can be opened and closed. The liner can bescrewed to the cover, so that it can be disengaged from it. The liner iscomprised of first- and second-side liner components each having anopening through which the rotating shaft of the impeller can pass,front- and rear-side liner components that are U-shaped and that arepressed against the ends of the first- and second-side liner componentsand fixed on them, and liner components that are pressed against theupper ends of the first- and second-side liner components and the front-and rear-side liner components and fixed on them.

Another concept of the centrifugal apparatus for projecting shots ofthis invention includes an impeller in which a hub, impeller-sideplates, impeller blades, and a distributor are rotatably located on arotating shaft, an impeller cover surrounding the impeller, and a liner.The impeller cover is comprised of first and second cover componentslocated at right and left sides, front and rear cover components, and aceiling cover component that can be opened and closed. The linercomponents can be screwed to the impeller cover, so that it can bedisengaged from it.

The liner components are comprised of first- and second-side linercomponents having openings through which the rotating shaft of theimpeller can pass, front and rear side liner components that areU-shaped and that are pressed against the ends of the first andsecond-side liner components and fixed on them, a frame-liner componentthat is engaged with the upper ends of the first- and second-side linercomponents and the front- and rear-side liner components, and aceiling-side liner component that can be engaged with and disengagedfrom the frame-liner component. A labyrinthine structure is located atthe connecting surfaces between the ceiling-side liner component and thefirst- and second-side liner components. The labyrinthine structure hasfour portions bent along the direction of the projection of theprojecting members. The ceiling-side liner can be pressed against theimpeller cover by a fixing member located on the impeller cover, andfixed on it.

A further concept of the centrifugal apparatus for projecting shots ofthis invention includes a protecting member for an impeller cover. Theprotecting member includes the impeller cover surrounding the front,rear, left, right, and ceiling sides of an impeller, first- andsecond-side liner components to protect the left and right sides of theimpeller cover, front- and rear-side liner components to protect thefront and rear sides of the impeller cover, a ceiling-side linercomponent to protect the ceiling side of the impeller cover, and aframe-liner component. The impeller cover comprises first- andsecond-side cover components having openings at the left and rightsides, plate-like front and rear-side cover components at the front andrear sides, and a ceiling-side cover component that can be opened andclosed at the upper side. The impeller cover is generally formed as abox shaped as a trapezoid. The first- and second-side liner componentsare generally shaped like trapezoids and have openings at the centerthrough which the first- and second-side plates pass. The first- andsecond-side liner components are fixed on the impeller cover by screws.The front and rear-side liner components are formed as rain gutters thatare U-shaped and inclined. The front- and rear-side liner components arepressed against and fixed on the right- and left ends of the first- andsecond-side liner components by bolts that are passed through the frontand rear plates of the impeller cover. A labyrinthine structure islocated at the connecting surfaces between the ceiling-side linercomponent and the first and second-side liner components. Thelabyrinthine structure comprises four portions bent in the direction ofthe projection of shots. The frame-liner component is shaped as a loopthat comprises a vertical plate to define an opening so that the upperends of the liner components that are engaged, pressed, and fixed withinthe impeller cover may pass through the opening. The frame-linercomponent is engaged with these upper ends. The ceiling-side linercomponent has a looped-projection formed along its periphery on itslower surface. The looped-projection is inserted into a U-shaped grooveformed by the upper ends of the side-liner components and the verticalplates of the frame-liner component. The ceiling-side liner component ispressed down by a fixing member that is located on the impeller coverand fixed on the frame-liner component.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a cross-sectional and vertical view of an embodiment of thecentrifugal projecting apparatus of this invention.

FIG. 2 is a view along the arrow A—A of FIG. 1.

FIG. 3 is a view along the arrow B—B of FIG. 1.

FIG. 4 is a view of a broken liner.

DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

Based on FIGS. 1-4 an embodiment of this invention is now explained.FIG. 1 shows a centrifugal apparatus for projecting shots. It also showsa plate 1 of a cabinet that has an opening. A plate 2 has an opening.The plate 2 is located on the plate 1 such that these openings coincidewith each other. A bearing 3 is fixed on the upper surface of the base2. The bearing 3 holds a rotating shaft. An impeller R is fixed by a hub4 to the end of the rotating shaft, and faces the openings.

Based on FIG. 1 the impeller R is now explained. A first-side impellerplate 5 is fixed on the front side of the hub 4. The first-side impellerplate 5 is connected to a second-side impeller plate 5A by a stay boltso that spacing is formed between them. Many impeller blades 6, 6 areradially located between the first-and second-side impeller plates 5, 5Aand are engaged with and fixed on them. A distributor 7 is fixed on thefirst-side impeller plate 5 within the bases of the impeller blades 6,6. A control cage 8 is arranged on the outer surface of the distributor7. The control cage is inserted into the opening of the second-sidecover component 21A and fixed on it. An opening of a nozzle 10 isconnected to the control cage 8. The nozzle 10 is fixed on the impellercover 20 by a cramping member 11, as explained below.

Next, based on FIGS. 1, 2, and 3 the impeller cover 20 is explained. Itis formed as a box shaped as a trapezoid. The bottom of it is open andarranged in line with the opening of the base 2, so that the impellercover 20 can cover the impeller R.

The front and rear side parts of the impeller cover 20 are the front-and rear-side cover components 20A, 20A (FIGS. 2 and 3). At the rightside of the impeller cover 20, the first-side cover component 21 islocated (FIG. 1). The first-side cover component 21 has an opening intowhich the bearing 3 is inserted, so that the outer surface of thebearing is engaged with the first-side cover component 21. At the leftside of the impeller cover 20, the second-side cover component 21A islocated (FIG. 1). The second-side cover component 21A has an openinginto which the control cage 8 is inserted, so that the outer surface ofthe control cage 8 is engaged with the second-side cover component 21A.The upper part of the impeller cover 20 is a ceiling cover 22. Theceiling cover 22 can be removed by means of rotating cramp-type screws23, 23 (FIGS. 2 and 3), which are put at the front and rear positions ofthe impeller cover 20.

Based on FIG. 4, arranging and combining the side liner components arenow explained. The first-side liner component 31 is screwed by screws32, 32 and nuts that are positioned at four up-and-down positions (as inFIG. 2) on the inner surface of the first-side cover component 21 (FIG.1). The first-side liner component 31 is shaped like a trapezoid. It hasan opening at the center through which the first-and second-sideimpeller plates 5, 5A can pass. The second-side liner component 31A isscrewed through a horseshoe-like spacer 33 by screws 32A, 32A and nutson four up-and-down positions (as in FIG. 3) on the inner surface of thesecond-side cover component 21A. The horseshoe-like spacer 33 is used toadjust the distance between the second-side cover component 21A and thesecond-side liner component 31A. The second-side liner component 31A isshaped as a trapezoid and has an opening at the center through which thesecond-side impeller plate 5A can pass.

At the front and rear sides of the first- and second-side linercomponents 31, 31A (the left and right sides in FIGS. 2 and 3), thefront- and rear-side liner components 34, 34A are located on the front-and rear-side cover components 20A, 20A of the impeller cover 20. Thefront- and rear-side liner components 34, 34A are U-shaped, like a raingutter, and inclined (FIG. 4).

The front and rear-side liner components 34, 34A can be removed from thefront- and rear-side cover components 20A, 20A. The front- and rear-sideliner components 34, 34A are pressed against the front- and rear-sidecover components 20A, 20A by means of pressing bolts 36, 36A located onbrackets 35, 35A, and are fixed on them. Thus, when shots are jammedbetween threads of the bolts 36, 36A, those bolts are replaced by newones or repaired after they are removed from the front- and rear-sidecover components 20A, 20A.

The frame-liner component 37 engages the upper ends of the first andsecond-side liner components 31, 31A and the front and rear-side linercomponents 34, 34A. The frame-liner component 37 is shaped as a loop toform an opening through which the upper ends of the first andsecond-side liner components 31, 31A and the front and rear-side linercomponents 34, 34A pass. A ceiling-side liner component 39 is located onthe frame-liner component 37. The ceiling-side liner component 39 has alooped projection 38 at its lower surface. The looped projection 38 isinserted into a looped and U-shaped groove that is defined by the upperends of the side liner components 31, 31A, 34, 34A and the frame-linercomponent 37.

A labyrinthine structure is formed at the connecting part between theceiling-side liner component 39 and the first- and second-side linercomponents 31, 31A. The labyrinthine structure has four bent points bentin the direction of the projection of shots.

The ceiling-side liner component 39 is pressed down by hook-like members24, 24 (FIGS. 2 and 3). The members are located at the front and rearpositions of the upper ends of the impeller cover 20. Alternatively,instead of the hook-like members 24, 24, the ceiling-side linercomponent 39 may be pressed by bolts that pass through the ceiling cover22.

Next, how some of the liner components are exchanged is explained. Whenthe ceiling-side liner component 39, which tends to be relatively easilyabraded, is exchanged, the rotating cramp-type screws 23, 23 (FIGS. 2and 3) are loosened and dislocated, and then the ceiling cover 22 isremoved. Then, the hook-like members 24, 24 are rotated to extend beyondthe ceiling-side liner component 39. Then, the component 39 is taken outfrom the opening of the impeller cover 20. A new liner component is putin place of the component 39.

When the front- and rear-side liner components 34, 34A are exchanged,first, the above operations are carried out until the ceiling-side linercomponent 39 is removed. Then, the frame-liner component 37 is manuallytaken out. Then, one of the bolts 36, 36A that screws the abraded linercomponent is loosened so that the abraded side liner component can bepulled up in the same direction that it is inclined. In place of theliner component a new one is put in.

When the first and second-side liner components 31, 31A, which arerelatively slowly abraded, are exchanged, first, the above operationsare carried out until the front- and rear-side liner components areremoved. Then, the cramping member 11 is removed so that both thecontrol gage 8 and the distributor 7 can be pulled toward the side wherethe nozzle 10 is located. Then, the impeller blades 6, 6 are pressedtoward the central opening at the space between the impeller-side plates5, 5A, and are pulled out toward the side where the nozzle 10 islocated, as in the case of the control gage 8.

Then, the screws 32A, 32A, which screw the second-side cover component21A, the spacer 33, which is shaped as a horseshoe, and the second-sideliner component 31A, are loosened and pulled out. Then, thehorseshoe-shaped spacer 33 is pulled up, and the second-side linercomponent 31A is slightly moved to the nozzle 10, so as to allow thesecond impeller-side plate 5A to pass through the opening, in relationto it, of the second-side liner component 31A. Then, the second-sideliner component 31A is moved up and taken out of the upper opening ofthe impeller cover 20.

Then, the screws 32, 32, which screw the first-side cover component 21,and the first-side liner component 31, are loosened and pulled out.Then, the first-side liner component 31 is moved to allow the first andsecond impeller-side plates 5, 5A to pass through the opening, inrelation to it. Then, as in the case of the second-side liner component31A, the first-side liner component 31 is moved up to be taken out ofthe upper opening of the impeller cover 20. The first and second-sideliner components 31, 31A are replaced by new liner components.

As in FIGS. 1, 2, and 3, the ceiling-side liner component 39 isconnected to the upper ends of the side liner components 31, 31A, 34,and 34A by the pressing members (hook-like members 24, 24) pressing theceiling-side liner component 39, so that the ceiling-side linercomponent 39 is fixed on the upper ends. Also, at the connecting partbetween the ceiling-side liner component 39 and the first- andsecond-side liner components 31, 31A, a labyrinthine structure that hasat least four bent points bent in the direction of the projection of theshots is located, so that shots can definitely be prevented fromprojecting through the connecting part.

Also, the first and second-side liner components 31, 31A are connectedto the front and rear-side liner components 34, 34A by pressing thefront and rear-side liner components 34, 34A against the first- andsecond-side liner components 31, 31A using the pressing bolts 36, 36A,so that the first- and second-side liner components 31, 31A are fixed onthe front- and rear-side liner components 34. Thus, shots can definitelybe prevented from being projected through the connecting part betweenthe first- and second-side liner components 31, 31A and the front- andrear-side liner components 34, 34A. Also, it can be assured that theimpeller cover is prevented from being abraded.

This invention allows liner components to be pressed against and fixedon an impeller cover. Thus, exchanging liner components for new ones iseasy. Also, the connecting portions are closely fitted. Thus, shots canbe prevented from being projected through the connecting portions. Also,the impeller cover can be prevented from being abraded.

What is claimed is:
 1. A centrifugal projecting apparatus for projectingmembers, said apparatus comprising an impeller having radially locatedimpeller blades and spaced first and second side impeller plates towhich the blades are fixed, an impeller cover that surrounds front,rear, left, right, and ceiling sides of the impeller, said impellercover having first and second side cover components having openings atleft and right sides of said impeller, plate-like front and rear sidecover components at front and rear sides of said impeller, and amoveable ceiling side cover component at an upper side of said impeller,said impeller cover being generally shaped like a box formed as atrapezoid, first and second side liner components located inside of andto protect the left and right sides of the impeller cover, front andrear side liner components located inside of and to protect the frontand rear sides of the impeller cover, a ceiling-side liner componentlocated inside of and to protect the ceiling side of the impeller cover,and a frame liner component for holding the first and second side linercomponents, front and rear linear components and ceiling side linercomponent together, wherein said first and second side liner componentsare generally shaped like trapezoids and have openings at the centerthereof through which the first and second side impeller plates canpass, said first and second side liner components being fixed to theimpeller cover by screws, said front and rear side liner components aregenerally U-shaped and inclined and are pressed against and fixed onright and left ends of the first and second side liner components bybolts that pass through the front- and rear-side cover components of theimpeller cover, a labyrinthine structure is formed at the connectingsurfaces between the ceiling side liner component and the first- andsecond-side liner components, said labyrinthine structure having atleast four bent points bent in the direction of the projection of theprojecting members to prevent the members from passing through saidconnecting surfaces, said frame liner component is shaped as a loophaving a vertical plate that defines an opening through which upper endsof the first and second and front and rear liner components pass and areengaged with, pressed against, and fixed on the impeller cover, and saidceiling side liner component has a looped-projection 38 formed along theperiphery of a lower surface thereof, said looped-projection beinginserted into U-shaped grooves defined in the upper ends of the firstand second and front and rear liner components and into the verticalplate of the frame-liner component, said ceiling-side liner componentbeing pressed and held in place by a fixing member located on theimpeller cover so that it is fixed on the frame-liner component.
 2. Theapparatus of claim 1 wherein the angle between each of the front andrear side liner components and the ceiling side liner component is fromabout 50 degrees to 80 degrees.
 3. The apparatus of claim 1 wherein thesecond side liner component is screwed to the impeller cover through aspacer that is shaped as a horseshoe so as to adjust the distancebetween them.
 4. The apparatus of claim 1 wherein the ceiling side linercomponent is pressed down and fixed on the frame liner component by hookmembers that are located on upper ends of the right and left sides ofthe impeller cover.
 5. The apparatus of claim 1, 2, or 3 wherein thebolts are positioned by brackets that are removable from the front andrear side cover components.